• Archives of Pharmacal Research
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• 제19권5호
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• pp.400-405
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• 1996

In vitro studies were conducted to dertermine the frequency rate of spontaneous resistance to LB20304 and to dertermine whether cross-resistance to other antimicrobial agents develops. In eight strains of bacteria, the frequency of mutation to LB20304 at the concentrations of four and eight times the minimal inhibitory concentration(MIC) ranaged from less than 4.0 ${\times}$ $10^{-10}$ to 2.2 $\{times}$ $10^{-10}$ . These results were similar to those founf for other new fluoroquinolones. THe development of stepwise resistance was determined by repeated subculture in broth in the presence of increasing concentration of the compounds. Exposure of bacteria to increasing concentrations of LB20304 resulted in the selection of organisms with higher MICs. There were 4- to 128-fold increases in the MIC of LB20304 for bacterial strains of Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli and Pseudomonas aeruginosa. However, those strains selected after repeated exposure were well within the susceptibility range for LB20304 except for Pseudomonas aeruginosa. The resistant isolates selected with LB20304 showed cross-resistance when tested against ciprofloxacin and vice versa.

• Journal of Veterinary Science
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• 제19권6호
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• pp.808-816
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• 2018

Bacterial biofilms have been demonstrated to be closely related to clinical infections and contribute to drug resistance. Berberine, which is the main component of Coptis chinensis, has been reported to have efficient antibacterial activity. This study aimed to investigate the potential effect of a combination of berberine with ciprofloxacin (CIP) to inhibit Salmonella biofilm formation and its effect on expressions of related genes (rpoE, luxS, and ompR). The fractional inhibitory concentration (FIC) index of the combination of berberine with CIP is 0.75 showing a synergistic antibacterial effect. The biofilm's adhesion rate and growth curve showed that the multi-resistant Salmonella strain had the potential to form a biofilm relative to that of strain CVCC528, and the antibiofilm effects were in a dose-dependent manner. Biofilm microstructures were rarely observed at $1/2{\times}MIC/FIC$ concentrations (MIC, minimal inhibition concentration), and the combination had a stronger antibiofilm effect than each of the antimicrobial agents used alone at $1/4{\times}FIC$ concentration. LuxS, rpoE, and ompR mRNA expressions were significantly repressed (p< 0.01) at $1/2{\times}MIC/FIC$ concentrations, and the berberine and CIP combination repressed mRNA expressions more strongly at the $1/4{\times}FIC$ concentration. The results indicate that the combination of berberine and CIP has a synergistic effect and is effective in inhibiting Salmonella biofilm formation via repression of luxS, rpoE, and ompR mRNA expressions.

• Journal of Veterinary Science
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• 제22권6호
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• pp.41.1-41.14
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• 2021

Background: Our previously prepared ceftiofur (CEF) hydrochloride oily suspension shows potential wide applications for controlling swine Streptococcus suis infections, while the irrational dose has not been formulated. Objectives: The rational dose regimens of CEF oily suspension against S. suis were systematically studied using a pharmacokinetic-pharmacodynamic model method. Methods: The healthy and infected pigs were intramuscularly administered CEF hydrochloride oily suspension at a single dose of 5 mg/kg, and then the plasma and pulmonary epithelial lining fluid (PELF) were collected at different times. The minimum inhibitory concentration (MIC), minimal bactericidal concentration, mutant prevention concentration (MPC), post-antibiotic effect (PAE), and time-killing curves were determined. Subsequently, the area under the curve by the MIC (AUC_0-24h/MIC) values of desfuroylceftiofur (DFC) in the PELF was obtained by integrating in vivo pharmacokinetic data of the infected pigs and ex vivo pharmacodynamic data using the sigmoid E_max (Hill) equation. The dose was calculated based on the AUC_0-24h/MIC values for bacteriostatic action, bactericidal action, and bacterial elimination. Results: The peak concentration, the area under the concentration-time curve, and the time to peak for PELF's DFC were 24.76 ± 0.92 ㎍/mL, 811.99 ± 54.70 ㎍·h/mL, and 8.00 h in healthy pigs, and 33.04 ± 0.99 ㎍/mL, 735.85 ± 26.20 ㎍·h/mL, and 8.00 h in infected pigs, respectively. The MIC of PELF's DFC against S. suis strain was 0.25 ㎍/mL. There was strong concentration-dependent activity as determined by MPC, PAE, and the time-killing curves. The AUC_0-24h/MIC values of PELF's DFC for bacteriostatic activity, bactericidal activity, and virtual eradication of bacteria were 6.54 h, 9.69 h, and 11.49 h, respectively. Thus, a dosage regimen of 1.94 mg/kg every 72 h could be sufficient to reach bactericidal activity. Conclusions: A rational dosage regimen was recommended, and it could assist in increasing the treatment effectiveness of CEF hydrochloride oily suspension against S. Suis infections.

• 생약학회지
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• 제43권4호
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• pp.323-327
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• 2012

Acne, also known as Acne vulgaris, is a common disorder of human skin involving the sebaceous gland and Propionibacterium acnes (P. acnes). The purpose of this study was to demonstrate whether anti-acne herbal complex (AAHC), a functional extract from herbal complex can be used for acne treatment as a natural product. We first demonstrated anti-acne activity of AAHC in mouse acne model. Acne was induced by injecting P. acnes on the backside $2{\times}10^7$ CFUs in ICR mice and then the mice were treated with AAHC by dermal application once daily. ACFREE$^{(R)}$ (clindamicin phosphate) was used as a positive control. Treatment with AAHC decreased the P. acnes-induced skin swelling and inflammation. AAHC treatment significantly decreased serum DHT concentration in acne-induced mice. Especially, treatment of 20% AACH in mice was more effected than 40%. We next evaluated the antimicrobial property of AAHC against P. acnes, Staphylcococcus aureus (S.aureus), and Escherichia coli (E. coli). Incubation of P. acnes, S. aureus, and E. coli with AAHC showed minimal inhibitory concentration (MIC) values against the bacterial growth lower. Alamar blue method was also carried for the antibacterial activity. It was effectively MIC level at 6.25% of P. acnes. AAHC effectively inhibited the growth of S. aureus and E. coli at 0.097% on MIC level, respectively. Our results showed the potential of using AAHC as an alternative treatment for antibiotic therapy of acne and the application of AAHC as a herbal medicine for acne treatment.

• 동의생리병리학회지
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• 제18권6호
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• pp.1740-1745
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• 2004

In order to evaluate the in vitro synergic effect of Eunkyo-san, with quinolone antibiotics, rufloxacin (RUFX), the minimal inhibitory concentration (MIC), MIC50 and MIC90 of single use of quinolones and concomitant treatment with Eunkyo-san against 9 strains of aerobic gram positive bacteria. The obtained results were as follows : In the case of aerobic gram positive bacteria, the MIC, MIC50 and MIC90 against Staphylococcus aureus, Staphylococcus aureus smith, Staphylococcus epidermidis, Staphylococcus pyogens, Streptococcus pneumoniae Type Ⅰ, Type Ⅱ and Type Ⅲ was significantly decreased in concomitant treated groups with Eunkyo-san compared to those of single treated groups of RUFX, respectively. However, no significant changes were demonstrated against Bacillus subtilis and Enterococcus faecalis. In conclusion, the in vitro antibacterial activity of RUFX were increased against some strains of aerobic gram positive strains, especially, pneumococcus such as Staphylococcus and Streptococcus by concomitant use of Eunkyo-san.

• 대한한방내과학회지
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• 제26권3호
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• pp.521-532
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• 2005

Objectives & Methods : In order to evaluate the in vitro synergic effects or Eunkyo-san which is a traditional poly-herbal formula that has been used in the treatment of respiratory diseases in oriental medicine, and quinolone antibiotics, rufloxacin (RUFX) and iprofloxacin(CPFX), experimentation was designed to determine minimal inhibitory concentration(MIC), $MIC_{50}\;and\;MIC_{90}$ of single use of quinolones and concomitant treatment with Eunkyo-san against 5 strains of aerobic gram negative bacteria, Escherichia coli, Klebsiella peumoniae, Hemophilus influenzae, Citrobacter freundii and Pseudomonas aeruginosae. Result : In the case of aerobic gram negative bacteria, the MIC, $MIC_{50}\;and\;MIC_{90}$ against Klebsiella peumoniae and Citrobacter freundii significantly decreased in concomitant-treated groups with Eunkyo-san compared to those of single-treated groups of RUFX and CPFX, respectively. However, no significant changes were demonstrated against Echerichia coli, Hemophilus influenzae and Pseudomonas aeruginosae. Conclusion : According to these results, concomitant use of Eunkyo-san against some strains of aerobic gram-negative bacteria dramatically increases in vitro antibacterial activity of RUFX and CPFX, and the increase and selectivity of antibacterial activities against these strains is attributable to Eunkyo-san, and not RUFX or CPFX activity.

• 치위생과학회지
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• 제11권1호
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• pp.37-40
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• 2011

Triterpenoid saponins 유도체인 OA와 UA가 치아우식증 원인균종의 하나인 Streptococcus downei의 표준균주(ATCC $33748^T$) 및 임상균주(4주)에 대하여, 액체배지희석법을 이용한 MIC값 측정 및 time-kill 분석법을 통한 살균작용 유무를 측정하여 다음과 같은 결과를 얻었다. 1. S. downei ATCC $33748^T$ 및 S. downei 임상균주(4주)들의 OA 대한 MIC 값은 $8{\mu}g/ml$로 동일하였고, UA의 대한 MIC 값은 S. downei 표준균주와 임상균주 간에 차이가 있었다. 2. Time-kill 분석법을 실시한 결과 OA와 UA는 S. downei $33748^T$에 대하여 $2{\times}MIC$ (각각 $16{\mu}g/ml$과 $8{\mu}g/ml$) 이상의 농도에서 살균작용을 갖는다는 것을 알 수 있었다. 이상의 연구결과를 종합할 때, triterpenoid saponins 유도체인 OA와 UA는 뮤탄스 연쇄상구균 중 최근에 사람의 구강 내 치면세균막에 서식하는 것으로 밝혀진 S. downei,에 대해 살균제로 작용할 수 있음을 알 수 있었다.

• 동의생리병리학회지
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• 제19권3호
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• pp.684-689
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• 2005

In order to evaluate the in vitro synergic effect of Mahwangyounpae-tang which was a traditional poly-herbal formula has been used in the treatment of respiratory diseases in oriental medicine, and quinolone antibiotics, ciprofloxacin (CPFX), the minimal inhibitory concentration (MIC), $MIC_{50}$ and MIC90 of single use of quinolones and concomitant treatment with Mahwangyounpae-tang against 5 strains of aerobic gram negative bacteria, Escherichia coli, Klebsiella peumoniae, Hemophilus influenzae, Citrobacter freundii and Pseudomonas aeruginosae. The obtained results were as follows : In the case of aerobic gram negative bacteria, the MIC, $MIC_{50}$ and $MIC_{90}$ against Klebsiella peumoniae and Pseudomonas aeruginosae was significantly decreased in concomitant treated groups with Mahwangyounpae-tang compared to those of single treated groups of CPFX, respectively. However, no significant changes were demonstrated against Echerichia coli, Hemophilus influenzae and Citrobacter freundii. According to these results, it is considered as the in vitro antibacterial activity of CPFX was dramatically increased by concomitant use of Mahwangyounpae-tang against some strains of aerobic gram negative bacteria and the increase and selectivity of antibacterial activities against strains were chosen by the selectivity of Mahwangyounpae-tang not CPFX activity.

• 한국미생물·생명공학회지
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• 제22권2호
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• pp.158-163
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• 1994

Microorganisms capale of utilizing linear alkylbenzene sulfonates(LAS) as sole carbon source were isolated from industrial effluent by using LAS agar plates. The isolated strains were identified as Salmonella sp(BC-2) and Escherichia sp.(BC-3) from the results of morphological, cultural and biochemical tests. The optimal condition for the growth and biodegradation of LAS was the initial pH 7.0 and LAS concentration 0.1%. The isolated BC-2 and BC-3 strains harbored plasmid and LAS-degrading activity was lost when the plasmids were cured by mitomycin C. The plasmids were transformed into E. coli and transformants have the LAS-degrading activity. Isolated strains were examined for primary biodegradation rate of LAS in the medium by methylene blueactive substance(MBAS) method. Of these isolates, BC-2 and BC-3 strains degradated LAS upto 60% and high resistant to CdCl$_{2}$ and HgCl$_{2}$. Isolated strains were sensitive to chloramphenicol, kanamycin, rifampicin, streptomycin and tetracycline but resistant to ampicillin and lincomycin.] Its minimal inhibitory concentration(MIC) for ampicillin was more than 1500 $\mu $g/ml.

• 한국식품과학회지
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• 제34권6호
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• pp.1073-1078
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• 2002

국산 대나무(맹종죽, 왕대, 솜대, 조릿대, 오죽) 70% 에탄올 추출물을 이용하여 천연 보존제로서의 특성 및 가능성을 검토하였다. 추출물의 항균활성은 주요 식중독균 10종으로 시험하였는데, 모든 대나무 줄기 추출물은 각 균주에 대해 항균력을 보였으나, 잎 추출물은 줄기 추출물에 비해 약한 항균성을 보이거나 균주에 따라서는 전혀 항균성을 나타내지 않았다. 특히, Staphylococcus aureus와 Streptococcus mutans에 대하여 모든 추출물이 비교적 높은 항균활성을 보였다. 왕대줄기 추출물의 MIC(minimal inhibitory concentration)는 이들 균주에 대해 각각 $10\;{\mu}L/disc,\;20\;{\mu}L/disc$ 이상의 농도에서 억제되었다. 왕대 줄기 추출물의 생육저해효과는 Staphylococcus aureus와 Streptococcus mutans의 성장에 대하여 조사하였다. 이들 균의 성장은 0.5% 농도일 때 억제되었고 1%일 때 완전히 억제되었다. $60,\;80,\;100^{\circ}C$에서 60분, $121^{\circ}C$에서 15분간 열처리한 후 이들 균주에 대해 생육 저해환을 측정한 결과 상기의 모든 열처리에 의해서도 무열처리군과 비교하여 볼 때 항균력의 차이가 없어 열에 매우 안정하였다. 이와 같은 결과로 미루어 보아 왕대줄기 70% 에탄올 추출물은 향후 천연보존제의 원료로 사용할 수 있을 것으로 보인다.